Multiple-speed drill press



Sept. 4, 1951 NICHOLS 2,566,579

MULTIPLE SPEED DRILL PRESS Filed April 8, 1950 2 Sheets-Sheet 1 Sept. 4, 1951 c s 2,566,579

MULTIPLE SPEED DRILL PRESS Filed April 8, 1950 2 Sheets-Sheet 2 Patented Sept. 4,, 1951 UNITED STATES PATENT OFFICE 6 Claims.

My invention relates generally to drill press structure and more specifically to speed-change mechanism for drill presses.

Heretofore, a pair of stepped-cone pulleys connected by an endless belt has been utilized to effect changes in the speed of rotation of a drill bit-equipped spindle in drill presses. This arrangement permits but a relatively few different rates of rotary speed of the spindle, and the correct drilling speed for a particular drilling operation is not often achieved. The principal object of my invention is, therefore, the provision of means, whereby a greater number of drill speeds may be obtained in a drill press of the above type.

Another highly important object of my invention is the provision of means whereby a drill as set forth may be operated in a plurality of speed ranges, the different speeds within one range being faster or slower than the several drill speeds within another range.

Another object of my invention is the provision of a speed-change mechanism which may be readily adapted for use on a conventional drill press.

Another object of my invention is the provision of speed-change mechanism as set forth in which transfer of power to the drill spindle between different speed ranges may be quickly and easily accomplished.

Still another object of my invention is the provision of novel clutch means for frictionally looking the above transmission mechanism in a predetermined speed range.

A still further object of my invention is the provision of speed-change mechanism of the above type which is relatively simple and inexpensive to produce and install, and which is efficient and durable in use.

. Other highly important objects and advantages of my invention will become apparent from the following detailed specification, appended claims, and attached drawings.

Referring to the drawings, wherein like characters indicate like parts throughout the several views:

Fig. 1 is a view in side elevation showing a drill press built in accordance with my invention, some parts being broken away and some parts shown in section;

Fig. 2 is an enlarged transverse section taken substantially on the line 2--2 of Fig. 1;

Fig. 3 is a fragmentary axial section taken on the line 3- -3 of Fig. 1, on an enlarged scale; and

Fig. 4 is a fragmentary section taken on the line 4-4 of Fig. 3.

Referring with greater detail to the drawings, a drill press I is shown as comprising a base 2, a supporting post or column 3, a work-supporting table l mounted for vertical movements on the column 3 and a drill head structure 5. The column 3 is rigidly mounted in the base 2 and extends upwardly through a mounting boss integrally formed with the table 4. A clamping screw l working through the boss 6 and engaging the column 3 looks the table 4 in any desired set posi tion with respect to the base 2 and the head structure 5. Means for raising and lowering the table 4 comprises a gear rack 8 secured at its lower end to a collar 9 which encircles the lower end portion of the column 3 and is supported from the base 2 by suitable anti-friction bearings iii. A housing or the like ll is secured to the boss 6 and provides a bearing for a shaft I2 upon which is rigidly mounted a pinion l3 and a worm gear I l. The pinion [3 has meshing engagement with the gear rack 8 and the worm gear I4 meshes with a worm l5 journalled in the housing H. A shaft portion of the worm l5 extends outwardly of the housing I l and is rigidly secured to a crank or the like it which, when the clamping screw 7 is loosened, may be operated to raise or lower the table 4. When the locking screw 7 is loosened, the table 4 may be moved circumferentially about the column 3, the rack 8 likewise moving about the column 3 by reason of the mounting of the collar 9.

The head structure 5 includes a rear portion ll which encompasses the upper end portion of the column 3 and is locked in place by the conventional lock bolt I8. At its forward end, the head structure 5 is formed. to provide a generally cylindrical guide member IS in which is slidably mounted for axial movements a quill 20. The quill 20 is of conventional design and is adapted to be moved vertically in the guide member l9 by manipulation of a multi-spoked elevatin member 2| rotatably mounted in the head structure 5 and having rack and pinion engagement, not shown, with the quill 25] in the conventional manner. The customary locking lever for the quill 26 is indicated at 22.

The rear-end portion I? of the head structure 5 is provided with a laterally outwardly projectins lug 23- which is screw-threaded to receive an adjustment screw 24, the lower end of which has abutting engagement with annular plate 25 as indicated at 2B. The annular plate 25 is supported by a fixed collar 27 on the column 3 through the medium of anti-friction bearings Or the like 28. When the locking bolt 18 is loosened. the head structure 5 may be raised or lowere with respect to the base 2 by manipulat of the adjustment screw 24; or the head struc 5 may be rotated about the axis of the column, the weight thereof being supported on the bearings 28 through the screw 24 and the annular plate 25. r

A rotary spindle 29 extends axially through the vertical quill 20 'and is journalled in the opp end portions thereof by means of anti-friction bearings 30, one of which is shown. The spindle 29 is locked against axial movements with respect to the quill 20 in the conventional manner but is movable therewith axially of the guide member 19. The spindle 29 extends vertically above the'quillZfl, the upper end portion'thereof being splined as indicated at 3|.

Suitably mounted on the head structure 5 is a vertically disposed arm 32 to whichli si'rigidlynecured a pair of vertically spaced bearing brackets 33 and 34. The brackets 33 and aa'extenulatew ally outwardly toward and intersect the axis i of the spindle 29. At their outer ends, the brackets 33 and 34 are provided with anti-friotion 'bearings 35 in which is jouinalled a tubular sleeve 3 6, radially outwardly spaced Hom and conce n trio with the spindle 29 -At' its rapper end, the sleeve =38 is 'iprovided with -an enlarged head or clutch element 3? haVing a plurality 'of teeth'38 which p'roject axiallyoutwardly of:the upper end of T the :sleeve 36 a'n'd the 'side '-or working fa'ees of which diverge in a direction axially outwardly Of the sleeve 3li for a purpose whichwill herein'after become apparent; Rotarymotionis imparted to the sleeve 3 6 by' an electric motoror the like '39, the dri've- 'shaft '40 f which extends in spaced parallel r'elation to'the axis of the sleeve36. An endless V-bel-t 4| run's-over cooperating steps on'a pair of s'tp'ped cone pulleys 42 and 43 the former ofwhioh is mounted onthe sleeve 35 and .s'ecured tormotation therewith by a pair 'of set screws or-the-like=44, and the latter of which is rigidly niounted on the motor shaft 40 any suitable nianner. The sp'eedof rotation of the sleeve 36 is-variedloy shifting the belt 4| from one pair-of -c ooperating steps on the cone pulleys 42 and 43 to 'selectedother cooperating steps thereof. It will be seen by reference to Fig.- 1 that the m'ot'oi 39 is h'ingedly mcunted to the rear-end ortionl 1 or the lie'ad structure as'indicated at '45 to' expedite'imovement of the V-belt 4| from one pair of -;steps of the cone pulleys to 'another pair' tliereof,

Rotary motion is impartedto'the spindle 29 from the pulley '42 bymecli'anism including a shiftable clutch member 46 which -is splin'ed to cooperate with the spli ried p'ortion 3| of the spindle 29. Theshiftable clutch member lt oomprises a pair of abutting sleeves'al and Ell-and a shifter collar '49 "which encompasses l the abuttingend portions'of the sleeves 'Ml and lit and is rigidly locked thereto by set screws the like 56. The shiftablememberrde is mounted for rotary and axialsliding'movements in spaced antifriction bearings that are-contained ih' the outer ends of spacedhrackets fl whichextend laterally outwardly from-and are' rigi-dly secured 1 to the arm 32. Tlielower'end of thesleeve iais provided with 'a diametri'cally' enlarged head =53 having axially outwardly projecting clutch H teeth lor the like 54. The-sideor'workingfaees-of' the {teeth 54 diverge in'a direction-axiallyoutwardly 1 l the head 53 whereby to-"c'ooperate-- with the 3 Main workiri'g faces of clutch teeth 38 of theeveel when 'shiftable 'meinber il is m'o'ved q liwardly into clutching engagement there- -Q By 'reference'to Fig. 3,"-it--shou-ld'beobvicus that the"correspondingdivergence in the eraces' of the'eooperating clutch teeth 38 and 54 w111 tend-to 'liold theclutcmel'ements "31' and 53 in operating engagement 'du'rin'gopera tion of the press-once theyha've been moved into j clutching engagement.

The axially outer or upper 1 end of Y the sleeve sleeve 48 T or in an opposite direction from the working faoes o'fthe teeth54 on the head 53. .The clutch teeth 56 are adapted to have inter- "Ifieshing engagement with cooperating teeth 51 which'ipi' oject axially outwardly or downwardly from an enlarged head 58 on a tubular sleeve 59. The-teeth 5'7 engage the teeth 58 in the same manner-es vheretofore described in connection with the teeth 54 and 38 whereby to cause the clutch elements 55 and 53 to be held in operative engagement during rotation thereof when the shiftable l-memben lt is m'o'ved toward the sleeve 59. The :sleeve 59 I is :imou'nted in spaced antifriction bearings tfi carried one each bytoinesof a pair or vertically :spac'ed bearing bra'cleets :16 1 extending flate'rally outwardly. from and secured to" the upper'en'd of the arm 32. By reference to:Figs.'-l and 3, it will beseenthat the sleeve- 59 is in radially outwardly spaced .con-centricrelation to the spindle 29 and in axial alignment with theisleevett and the shiftable member ll.

Means for imparting rotary movement to :the sleeve 59 comprises transmission mechanism operatively associated with the stepped 'cone' pulleys 42. A j'ackshaft 26 2 in spaced parallelrelationship to the spindle 29, is journalled inSspa'ced bearing brackets' 63 and 54* rigidly' seeured to Ithe arm 32. A pair of endless V-"belts runs over -a pair of're'latively small fii'ghts'BG .on the stepped cone pulley 42 and a'relatively large double 'pulley Elfast'on one end portion of the jackshaft B2. A second pair of'Ie-ndless V-belts'liB runs-over various speeds slower than the various speeds of the cone pulley 42 and that the relative diameters of the pulleys-$9 and-57 c'auses rotation of the sleeve 59 at alowe'r speedthan that of the shaft '62. pulleys provide for a maximum speed of "the sleeve 59slower'than the minimumepeedof the sleeve 36. 7 By this'meansa apairiof separate speed ranges :is obtained in'the 'spindle'iil, thus do-u bling the fiexibilitylof the drill press and the capacity thereof for different drilling"operations I.provide' means forshiftingthe shiftable memloer- 46 from a neutral position shown in Figs. -1 and 3 :to a cl'utchengaged 1 position with either the relatively high speed-sleeve '36 or the'rel'a tively slow speed sleeve 59. This means oom-- prises a shifter lever or fork T72 equipped with a pair of axially aligned axial rollers 73 Working in a circ'umferentially extended groove "14 in the shifter collar 49. The'shifter'fork 12 is 'pivotally' mounted by means of I a washer equipped bolt 75 extending therethrough into a mounting plate'orthelike '1 Eweldd or otherwise securedto a pair of fingers '71 extending laterally outwardly 'o'neeach'from-eachpf the bearing brackets'52. A pair'offriction washerslt made fromanys'uitable material having a relatively high coeiiflci-v ent of friction are utilized to maintai'n'the' shifter fork" 12 ands-nimble "member 48 F in desired "set position, see particularly "Fig. 4;

The relative rdiametersiof the various handle 19 which extends laterally outwardly through an opening Ed in a housing or the like 8| mounted on the head structure 5.

From the above it should be obvious that when it is desired to operate the drill press in the low speed range, it is but necessary to manually move the handle 79 in a direction to cause the clutch teeth 5% to operatively engage the clutch teeth 51. On the other hand, when it is desired to operate the drill press in the high speed range, the handle '59 is moved in the opposite direction to cause the clutch teeth 5 to engage the teeth 38.

My invention has been thoroughly tested found to be completely satisfactory for the accomplishment of the objectives set forth; and while I have shown a commercial embodiment of my improved drill press structure, it should be obvious that same is capable of modification without departure from the spirit and scope or the invention as defined in the claims.

What I claim is:

1. In a device of the class described, a head structure, a spindle mounted for rotary move ments in said. structure, a drive shaft, a sleeve journalled for rotation in said head structure and concentric with said spindle, variable speed power transmission means associated with said drive shaft and sleeve for transmitting rotary movement to said sleeve at various speeds within a predetermined speed range, a second sleeve journalled for rotation in said head structure in axially spaced relation to said first mentioned sleeve and concentric with said spindle, power transmission mechanism cperatively associated with said first and second sleeves whereby rotary movements are imparted to second sleeve at various speeds within a speed range different from the range of speed of rotary movement of said first mentioned sleeve, opposed clutch elements on adjacent ends of said sleeves, and a shiftable clutch member keyed to said spindle for axial sliding movements with respect thereto into and out of driving engagement with either of said clutch elements independently of the other, whereby to impart rotary movements to said spindle in a selected speed range.

2. In a device of the class described, a head structure, a spindle mounted for rotary and axial movements in said head structure, a drive shaft, a sleeve journalled for rotation in said head structure and concentric with said spindle, variable speed power transmission means associated with said drive shaft and sleeve for transmitting rotary movement to said sleeve at various speeds within a predetermined speed range, a second sleeve journalled for rotation in said head structure in axially spaced relation to said first mentioned sleeve and concentric with said spindle, power transmission mechanism operatively associated with said first and second sleeves whereby rotary movements are imparted to said second sleeve at various speeds within a speed range different from the range of speed of rotary movement of said first mentioned sleeve, opposed tooth-equipped jaw clutch elements on adjacent ends of said sleeves, the working faces of the teeth of said clutch elements diverging in a direction axially outwardly of said sleeves,

.a shiftable member keyed to the spindle intermediate said sleeves for axial sliding movements with respect thereto, said shiftable member having a plurality of circumferentially spaced teeth at its opposite ends, the working faces of said teeth diverging in a direction corresponding iii) to the working faces of said clutch elements, whereby to prevent accidental disengagement of the teeth of said shiftable member from the clutch element engaged thereby, and means for moving said shiftable member into and out of clutching engagement with said clutch elements.

3. The structure defined in claim 2 in which the means for moving said shiftable member comprises a hand lever pivoted to said head structure, a shiftable collar on said shiftable member and engageable with one end of said lever, and friction elements between said lever and the head structure for frictionally holding said lever and shiftable member in desired set position.

l. In a device of the class described, a drillhead structure, a spindle mounted for rotary and axial movements in the head structure, a drive shaft in spaced parallel relationship to said spindle, a sleeve journalled for rotation in said head structure and concentric with said spindle, cooperating stepped cone pulleys on said drive shaft and said sleeve, an endless belt running over corresponding steps on said pulleys and shiftable thereon to vary the speed of rotation of said sleeve with respect to the drive shaft within a predetermined speed range, a second sleeve journalled for rotation in said head structure in vertically spaced axial alignment with said first mentioned sleeve and concentric with said spindle, a jackshaft journalled in said head structure in spaced parallel relation to said spindle and sleeves, cooperating pulleys fast on said sleeves and said jackshaft, endless belts running over said pulleys whereby to drive said jackshaft from said first mentioned sleeve and. to drive said second sleeve from said jackshaft, the relative sizes of said pulleys effecting various speeds of rotation of said second sleeve in a speed range different from that of the first mentioned sleeve, opposed clutch elements on adjacent ends of said sleeves, a shiftable clutch member keyed to said spindle for axial sliding movements with respect thereto into and out of driving engagement with either of said clutch elements independently of each other whereby to impart rotary movements to said spindle in a selected speed range, and means for moving said shiftable member into and out of clutching engagement with said clutch elements.

5. The structure defined in claim 4 in which the opposed clutch elements on said sleeves comprise axially projecting teeth which are adapted to engage cooperating teeth on opposite ends of said shiftable member, the working faces of the teeth of said clutch elements diverging in a direction axially outwardly of the sleeves, the working faces of the teeth in said shiftable member diverging in a direction corresponding to the working faces on the teeth on said clutch elements, whereby to prevent accidental disengagement of the teeth of said shiftable member from the clutch element engaged thereby.

6. The structure defined in claim 4 in which the means for moving said shiftable member comprises a hand lever pivoted to said hea structure, a shiftable collar on said shiftalq member and engageable with one end of S lever, and friction elements between said i and the head structure for frictionally lw said lever and shiftable member in desi set positions.

FRED L, CHOLS.

No references cited. 

